/*
 *    Copyright 2019 The aio-socket Project
 *
 *    The aio-socket Project Licenses this file to you under the Apache License,
 *    Version 2.0 (the "License"); you may not use this file except in compliance
 *    with the License. You may obtain a copy of the License at:
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package io.task.socket.plugins;

import io.task.socket.core.Config;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousSocketChannel;
import java.util.concurrent.ConcurrentLinkedQueue;

/**
 * 黑名单插件,smart-socket会拒绝与黑名单中的IP建立连接
 *
 * @author MDong
 * @version 2.10.1.v20211002-RELEASE
 */
public final class BlackListPlugin extends AbstractPlugin {

	private final ConcurrentLinkedQueue<BlackListRule> ipBlackList = new ConcurrentLinkedQueue<>();

	public BlackListPlugin() {
		System.out.println("aio-socket version: " + Config.VERSION + "; server kernel's black list plugin added successfully");
	}

	@Override
	public AsynchronousSocketChannel shouldAccept(AsynchronousSocketChannel channel) {
		InetSocketAddress inetSocketAddress = null;
		try {
			inetSocketAddress = (InetSocketAddress) channel.getRemoteAddress();
		} catch (IOException e) {
			System.out.println("get remote address error " + e);
		}
		if (inetSocketAddress == null) {
			return channel;
		}
		for (BlackListRule rule : ipBlackList) {
			if (!rule.access(inetSocketAddress)) {
				return null;
			}
		}
		return channel;
	}

	/**
	 * 添加黑名单失败规则
	 *
	 * @param rule .
	 */
	public void addRule(BlackListRule rule) {
		ipBlackList.add(rule);
	}

	/**
	 * 移除黑名单规则
	 *
	 * @param rule .
	 */
	public void removeRule(BlackListRule rule) {
		ipBlackList.remove(rule);
	}

	/**
	 * 黑名单规则定义
	 */
	public interface BlackListRule {
		/**
		 * 是否允许建立连接
		 *
		 * @param address .
		 * @return .
		 */
		boolean access(InetSocketAddress address);
	}
}
